./createdocker.sh newuser newpass

USERNAME=$1     <-- thus USERNAME=newuser
PASSWORD=$2     <-- thus PASSWORD=newpass

/usr/bin/sshpass -p $ORIGINALPASSWORD ssh -p $PORT -o StrictHostKeyChecking=no root@$IP $SCRIPT

SCRIPT="adduser $USERNAME;                                    <-- add newuser
echo -e $PASSWORDn$PASSWORD | (passwd --stdin $USERNAME);    <-- set newpass
echo ssh username: $USERNAME;
echo ssh password: $PASSWORD;
echo Instance Login Success;
exit"

[root@netunique docker-sshd]# ./signup_createdocker.sh newuser newpass
Instance Created
adduser newuser;echo -e newpassnnewpass | (passwd --stdin newuser);echo ssh username: newuser;echo ssh password: newpass;echo Instance Login Success;exit
Warning: Permanently added '[localhost]:32936' (RSA) to the list of known hosts.
Changing password for user newuser.
passwd: all authentication tokens updated successfully.    <-- appears 'set newpass' worked
ssh username: newuser
ssh password: newpass
Instance Login Success

[root@netunique docker-sshd]# ssh -p 32936 newuser@localhost
myuser@localhost's password:                   <-- here I type 'newpass'
Permission denied, please try again.           <-- here the login fails
myuser@localhost's password:

adduser newuser
echo -e "newpassnnewpass" | (passwd --stdin newuser)